Thanks for the info, BradC - I will dig them all out tomorrow and have another look although I think I threw the GasCat out years ago after Maplins would not replace it under warranty, but still have the Portasol and the Iroda (SolderPro50 from memory) The other two were no-name stubby cheapos from yard sales, one of which would erupt into flame from all joins and orifices at random moments.
BT